Document Type : Original research
Authors
1 Iran Polymer and Petrochemical Institute, 14965-115, Tehran, Iran
2 Leibniz-Institut für Polymerforschung Dresden e.V., D-01069, Dresden, Germany
Abstract
In this work, the effect of hexyl branch content on thermal behavior of a fractionated ethylene/1-octene copolymer with emphasis on high temperatures was investigated. The ethylene/1-octene copolymer was carefully fractionated to different fractions with homogenous hexyl branch (HB) content by preparative temperature rising elution fractionation (P-TREF) method. The P-TREF fractions were thermally analyzed via differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and evolved gas analysis (EGA). The P-TREF profile showed a short chain branch distribution (SCBD) of around 1.24. A linear relationship between P-TREF elution temperature (ET) and methylene sequence length (MSL) was presented. The DSC curves exhibited a monolithically increase in melting temperature (Tm) as well as crystallization temperature (Tc) by decreasing short chain branch (SCB) content. The calculated values of lamellae thickness suggested a linear function of SCB content and Tm. The TGA studies of P-TREF fractions depicted a two-stage thermal degradation behavior: pre-degradation and main degradation stages. Tmax for both pre-degradation and main degradation stages was increased for fractions with less hexyl branch content. As an interesting point the pre-degradation stage was found more intensified for more linear fractions. The concentration of main products was found to be affected by the content of hexyl branches using Py-GC-MS.
Keywords
Main Subjects
- Papageorgiou DG, Bikiaris DN, Chrissafis K (2012) Effect of crystalline structure of polypropylene random copolymers on mechanical properties and thermal degradation kinetics. Thermochimica Acta 543: 288-294
- Pourtaghi-Zahed H, Zohuri GH (2012) Synthesis and characterization of ethylene-propylene copolymer and polyethylene using α-diimine nickel catalysts. J Polym Res 19: 1-8
- Mirabella FM, Crist B (2004) Melting behavior of polyethylene/α-olefin copolymers: Narrow composition distribution copolymers and fractions from Ziegler–Natta and single-site catalyst products. J Polym Sci Pol Phys 42: 3416-3427
- Liu Z, Chen S, Zhang J (2011) Preparation and characterization of ethylene-butene copolymer (EBC)/mica composites. J Polym Res 18: 2403- 2413
- Zhang X-b, Li Z-s, Lu Z-y, Sun C-C (2002) Roles of branch content and branch length in copolyethylene crystallization: Molecular dynamics simulations. Macromolecules 35: 106- 111
- Mauler RS, Galland GB, Scipioni RB, Quijada R (1996) The effect of the ethylene pressure on its reaction with 1-hexene, 1-octene and 4-methyl- 1-pentene. Polym Bull 37: 469-474
- Gomari S, Ghasemi I, Karrabi M, Azizi H (2011) Organoclay localization in polyamide 6/ethylene-butene copolymer grafted maleic anhydride blends: the effect of different types of organoclay. J Polym Res 19: 1-11
- Pourtaghi-Zahed H, Zohuri GH, Ahmadjo S (2014) Unique microstructure analysis of ethylene-propylene copolymer synthesized using catalytic system based on α-diimine nickel complexes: a comparative study by 13C NMR technique. J Polym Res 21: 1-10
- Bensason S, Stepanov E, Chum S, Hiltner A, Baer E (1997) Deformation of elastomeric ethylene-octene copolymers. Macromolecules 30: 2436-2444
- Rabiej S, Goderis B, Janicki J, Mathot V, Koch M, Groeninckx G, Reynaers H, Gelan J, Włochowicz A (2004) Characterization of the dual crystal population in an isothermally crystallized homogeneous ethylene-1-octene copolymer. Polymer 45: 8761-8778
- Babu RR, Singha NK, Naskar K (2010) Effects of mixing sequence on peroxide cured polypropylene (PP)/ethylene octene copolymer (EOC) thermoplastic vulcanizates (TPVs). Part. II. Viscoelastic characteristics. J Polym Res 18: 31-39
- Sehanobish K, Patel R, Croft B, Chum S, Kao C (1994) Effect of chain microstructure on modulus of ethylene–α-olefin copolymers. J Appl polym Sci 51: 887-894
- Bensason S, Minick J, Moet A, Chum S, Hiltner A, Baer E (1996) Classification of homogeneous ethylene-octene copolymers based on comonomer content. J Polym Sci Pol Phys 34: 1301-1315
- Brady JM, Thomas EL (1988) Effect of short-chain branching on the morphology of LLDPE-oriented thin films. J Polym Sci Pol Phys 26: 2385-2398
- Mileva D, Zia Q, Androsch R (2010) Tensile properties of random copolymers of propylene with ethylene and 1-butene: Effect of crystallinity and crystal habit. Polym Bull 65: 623-634
- Galland GB, Mauler RS, de Menezes SC, Quijada R (1995) 13C-NMR study of ethylene/1-hexene and ethylene/1-octene copolymers obtained using homogeneous catalysts. Poly Bull 34: 599- 604
- Koivumäki J (1996) Properties of ethylene/1- octene, 1-tetradecene and 1-octadecene copolymers obtained with Cp2ZrCl2/MAO catalyst: Effect of composition and comonomer chain length. Polym Bull 36: 7-12
- Guo N, Li L, Marks TJ (2004) Bimetallic catalysis for styrene homopolymerization and ethylene-styrene copolymerization. Exceptional comonomer selectivity and insertion regiochemistry. J Am Chem Soc 126: 6542-6543
- Mileva D, Androsch R, Radusch H-J (2009) Effect of structure on light transmission in isotactic polypropylene and random propylene- 1-butene copolymers. Polym Bull 62: 561-571
- Vanden Eynde S, Mathot V, Höhne G, Schawe J, Reynaers H (2000) Thermal behaviour of homogeneous ethylene-1-octene copolymers and linear polyethylene at high pressures. Polymer 41: 3411-3423
- Starck P, Rajanen K, Löfgren B (2002) Comparative studies of ethylene–α-olefin copolymers by thermal fractionations and temperature-dependent crystallinity measurements. Thermochim Acta 395: 169-181
- Mileva D, Androsch R, Radusch H-J (2008) Effect of cooling rate on melt-crystallization of random propylene-ethylene and propylene-1- butene copolymers. Polym Bull 61: 643-654
- Alamo RG, Mandelkern L (1994) The crystallization behavior of random copolymers of ethylene. Thermochim Acta 238: 155-201
- Abbas-Abadi MS, Nekoomanesh N.M, Yeganeh H, Bozorgi B (2013) The effect of melt flow index, melt flow rate, and particle size on the thermal degradation of commercial high density polyethylene powder. J Therm Anal Calorim 114: 1333-1339
- Kebritchi A, Nekoomanesh M, Mohammadi F, Khonakdar HA (2015) The interrelationships between microstructure and melting, crystallization and thermal degradation behaviors of fractionated ethylene/1-butene copolymer. Iran Polym J 24: 267-277
- Kebritchi A, Nekoomansh M, Mohammadi F, Khonakdar HA (2015) The ablative behavior of high linear chains and its role in the thermal stability of polyethylene: A combined P-TREF− TGA study. Polym Int 64: 1316-1325
- Kebritchi A, Nekoomansh M, Mohammadi F, Khonakdar HA (2014) The role of 1-hexene comonomer content in thermal behavior of medium density polyethylene (MDPE) synthesized using Phillips catalyst. Polyolefins J 1: 117-129
- Kebritchi A, Nekoomanesh H. M, Mohammadi F, Khonakdar HA (2017) Effect of Microstructure of high density polyethylene on catalytic degradation: A comparison between nano clay and FCC. J Polym Environ 21: 1-10
- Cheruthazhekatt S, Pijpers TF, Mathot VB, Pasch H (2013) Combination of TREF, high-temperature HPLC, FTIR and HPer DSC for the comprehensive analysis of complex polypropylene copolymers. Anal Bioanal Chem 405: 8995-9007
- Assumption H, Vermeulen J, Jarrett WL, Mathias LJ, Van Reenen A (2006) High resolution solution and solid state NMR characterization of ethylene/1-butene and ethylene/1-hexene copolymers fractionated by preparative temperature rising elution fractionation. Polymer 47: 67-74
- Müller A, Hernandez Z, Arnal M, Sánchez J (1997) Successive self-nucleation/annealing (SSA): A novel technique to study molecular segregation during crystallization. Polymer Bull 39: 465-472
- Joe D, Golling FE, Friedemann K, Crespy D, Klapper M, Müllen K (2014) Anisotropic Supports in Metallocene-Catalyzed Polymerizations: Templates to Obtain Polyolefin Fibers. Macromol Mater Eng 299: 1155-1165
- Dorresteijn R, Nietzel S, Joe D, Gerkmann Y, Fink G, Klapper M, Müllen K (2014) Metallocene supported on porous and nonporous polyurethane particles for ethylene polymerization. J Polym Sci Pol Chem 52: 450-459
- De Rosa C, Auriemma F, Villani M, Ruiz de Ballesteros O, Di Girolamo R, Tarallo O, Malafronte A (2014) Mechanical Properties and Stress-Induced Phase Transformations of Metallocene Isotactic Poly (1-butene): The Influence of Stereodefects. Macromolecules: 47: 1053-1064
- Zhang M, Wanke SE (2003) Quantitative determination of short-chain branching content and distribution in commercial polyethylenes by thermally fractionated differential scanning calorimetry. Polym Eng Sci 43: 1878-1888
- Kakugo M, Miyatake T, Mizunuma K (1991) Chemical composition distribution of ethylene- 1-hexene copolymer prepared with titanium trichloride-diethylaluminum chloride catalyst. Macromolecules 24: 1469-1472
- Adisson E, Ribeiro M, Deffieux A, Fontanille M (1992) Evaluation of the heterogeneity in linear low-density polyethylene comonomer unit distribution by differential scanning calorimetry characterization of thermally treated samples. Polymer 33: 4337-4342
- Hosoda S (1988) Structural distribution of linear low-density polyethylenes. Polym J 20: 383-397
- Mortazavi SMM, Arabi H, Zohuri G, Ahmadjo S, Nekoomanesh M, Ahmadi M (2010) Copolymerization of ethylene/α-olefins using bis (2-phenylindenyl) zirconium dichloride metallocene catalyst: Structural study of comonomer distribution. Polym Int 59: 1258- 1265
- Hosoda S, Nozue Y, Kawashima Y, Suita K, Seno S, Nagamatsu T, Wagener KB, Inci B, Zuluaga F, Rojas G (2010) Effect of the sequence length distribution on the lamellar crystal thickness and thickness distribution of polyethylene: Perfectly equisequential ADMET polyethylene vs ethylene/α-olefin copolymer. Macromolecules 44: 313-319
- Gauthier E, Laycock B, Cuoq F-M, Halley P, George K (2013) Correlation between chain microstructural changes and embrittlement of LLDPE-based films during photo-and thermo-oxidative degradation. Polym Degrad Stabil 98: 425-435
- Wilfong DL,Knight G (1990) Crystallization mechanisms for LLDPE and its fractions. J Polym Sci Pol Phys 28: 861-870
- Zhang M, Lynch D, Wanke S (2001) Effect of molecular structure distribution on melting and crystallization behavior of 1-butene/ethylene copolymers. Polymer 42: 3067-3075
- Hosoda S, Kojima K, Furuta M (1986) Morphological study of melt-crystallized linear low-density polyethylene by transmission electron microscopy. Die Makromol Chem 187: 1501-1514
- Kebritchi A, Nekoomanesh H. M, Mohammadi F, Khonakdar HA (2014) The role of 1-hexene comonomer content in thermal behavior of medium density polyethylene (MDPE) synthesized using Phillips catalyst. Polyolefins J 2: 117-129
- Pielichowski K, Njuguna J (2005) Thermal degradation of polymeric materials. Rapra Technology, Show bury, UK
- Katritzky AR, Kuanar M, Slavov S, Hall CD, Karelson M, Kahn I, Dobchev DA (2010) Quantitative correlation of physical and chemical properties with chemical structure: Utility for prediction. Chem Rev 110: 5714-5789
- Lattimer RP (1995) Pyrolysis field ionization mass spectrometry of polyolefins. J Anal Appl Pyrolys 31: 203-225
- Mastral F, Esperanza E, Berrueco C, Juste M, Ceamanos J (2003) Fluidized bed thermal degradation products of HDPE in an inert atmosphere and in air–nitrogen mixtures. J Anal Appl Pyrolys 70: 1-17.
- Poutsma ML (1990) Free-radical thermolysis and hydrogenolysis of model hydrocarbons relevant to processing of coal. Energy Fuels 4: 113-131
- Kossiakoff A, Rice FO (1943) Thermal decomposition of hydrocarbons, resonance stabilization and isomerization of free radicals1. J Am Chem Soc 65: 590-595
)
